The fire started around 4:15 a.m. at Building G at the Gables Upper Rock Apartments on Upper Rock Circle. Montgomery County fire officials say the three-acre complex was 90 percent complete and expected to be finished in two to three weeks before this fire ripped through 150 units.

"The fire was huge. The orange glow was shining into my window and woke me up. After a while, I had to leave the apartment because the smoke was coming in," said Jessica Ainsworth, who lives in a neighboring building.

Fire officials believe gas tanks inside the building were possibly feeding the flames.